this verb does not follow a contracting pe-yud/vav pattern with the
retracted accent like vayyEshev.
most vayyiqtol's do not contract accents.
cf. other p"y: vayyirAsh and vayyiqAr.
this verb yatsaq is highly irregular (multiple, dialectical/idiolectical
forms), notice yeHezq'l 24.3 where the imperative is yetsoq !, and then
again 2K4.41 tsaq !

when doing 'immersion' teaching i use yetsoq, yitsqi, yitsqu, yitsOqna.
gotta choose a form and this feels best, though both bring smiles from
those here in jerusalem who listen in.